Boating season is only about 10 weeks away, and with it comes heightened concern about the potential spread of zebra mussels.

Besides attaching themselves to boats, motors and trailers, they can also hitchhike from lake to lake on docks, boat lifts and other equipment that will soon be dunked into water.

To lower that risk, a new state law requires mandatory training for those in the business of dock and boat services.

About 70 company owners and workers met this week in Chanhassen for the first of 21 training sessions to be held statewide.

"We need to get you up to speed to protect our lakes and to protect you," Jay Rendall, invasive species prevention coordinator for the Minnesota Department of Natural Resources, told the group.

Concern is high because invasive mussels litter beaches with razor-sharp shells, accumulate on boats and clog motors, and change the ecology of fisheries by consuming food that small fish need to survive. Lakeshore and resort owners worry that they also will lower property values and discourage tourism.

MORE CLASSES ARE ON TAP

The threat from the dock equipment is very real. Rose Lake in Otter Tail County and Lake Irene in Douglas County were contaminated with zebra mussels last fall when lakeshore owners purchased and installed used boat lifts that came from infested lakes.

Minnesota already has laws prohibiting transfer of invasive species, but this year it is ramping up its inspections and enforcement. The new law requires the extra training for "lake service providers" who are paid for work such as repairing, launching and storing boats and installing and removing buoys, docks and boat lifts.

Owners of those businesses must take the training, pass a test and apply for a three-year permit that costs $50. DNR officials estimate that 1,000 to 2,000 owners need to have permits, beginning this boating season. Their employees must take the training online and obtain a certificate at no charge.

"It provides another blanket of awareness among a sector that has their fingers in a lot of water bodies," said Dick Osgood, executive director of the nonprofit Lake Minnetonka Association. Zebra mussels were found there in 2010, and have spread rapidly in the heavily used lake.

Nooks and crannies

Jack Dukes, owner of Crows Nest Marine in Independence, said the training is a "step in the right direction," but raises a host of questions, including details about how and where decontamination will happen.

At some boat landings, DNR inspectors examine the exterior of boats and boat trailers, and interiors such as bilges, wet wells and bait buckets, to be sure all water has been drained. If zebra mussels are found, the state recommends high-pressure spraying with 140-degree water for 10 minutes to kill and remove them. Another method is to dry contaminated equipment for 21 days.

Bob Holz, owner of Bayside Marine Service in Excelsior, said that he has found zebra mussels in "every nook and cranny" of boats he services on Lake Minnetonka, and it's virtually impossible to "get them all out."

Bret Niccum, co-owner of Niccum Docks and Marine Group in Rockford, said the state hasn't done enough to address the biggest risk: boat owners who ignore or intentionally flout the rules. Niccum said watercraft owners should be required to take online training and pass a test as a condition of renewing their boat, canoe or personal watercraft licenses.

Others at the meeting said that fishing guides also should be required to receive training because they frequently move boats and trailers from lake to lake.

The state's technology system has been plagued by high-profile failures, and finding someone willing to head the department has proven challenging. "It keeps me up at night," Walz said in an interview.